Thousands of homeowners may see the value of their properties plummet after a court ruled that living near a wind farm decreases house prices.

In a landmark case, Jane Davis was told she will get a discount on her council tax because her £170,000 home had been rendered worthless by a turbine 1,000 yards away.

The ruling is effectively an official admission that wind farms, which are accused of spoiling countryside views and producing a deafening roar, have a negative effect on house prices.

It means many other families living in the shadow of the giant turbines could see thousands wiped off the value of their homes, as the Government pushes ahead with plans to build 7,000 more wind farms over the next decade to meet ambitious green targets.

Campaigners also fear ministers want to remove the legal right to complain about noise nuisance, condemning those who live near wind farms to years of blight and reducing the opportunity for them to resist expansion plans.

Mrs Davis, who launched a nationwide campaign after her own home was rendered worthless by the deafening roar of a wind farm, claims ministers are tabling an amended to the Planning Act which will remove eight crucial words that previously offered at least some protection to householders.

"For people living near wind farms, both now and in the future, it will be a disaster," she said.

"There are many, many people living in Middle England who have worked hard all their lives and yet will see the values of their homes suddenly diminish.

"This isn't about Nimbyism, but the rights of ordinary people to live a normal life."

Mrs Davis, 52, a retired nurse, lives 1,017 (930m) from a wind farm at Deeping St Nicholas, Lincolnshire. Her husband, Julian, 43, originally bought the property from the county council and the couple had planned to extend it.

But the noise generated by the turbines is so severe, particularly when certain winds make all the blades rotate in unison, that it left the Davises unable to sleep. They currently live in a rented house a few miles away.

"It's just like the effect you get in a car when the sun roof is open or a window at the back is open. In a car you can do something about it. But if it's in your house and is coming from a giant turbine a few yards away, you can do nothing," said Mrs Davis.

Local estate agents have acknowledged that the house, worth £170,000 before the wind farm was built in 2006, is now so severely blighted that no one is likely buy it.

Earlier this week the Davises won a landmark victory that reduced their council tax banding.

Although financially the difference is minimal, the reduction was granted on the basis that their home had been blighted by noise "on the balance of probability".

Furthermore, the couple secured the ruling in the absence of a statutory noise nuisance - a fact that brought dismay to wind farm operators.

But Mrs Davis now fears the imminent change in legislation will turn the advantage back to the wind farm lobby, which is planning to build 4,000 turbines across the countryside - double the current number - and increase the number of those offshore from 150 to 3,000 by 2020.